EghtesadOnline: Iran’s Corruption Perceptions Index dropped by two points in 2019 to score 26 out of 100, according to a report by the global graft monitor Transparency International.

As per the CPI scale, zero is perceived to be highly corrupt while 100 is perceived to be very clean. The country’s ranking also fell by eight places and is now ranked 146th out of 180 countries, according to Financial Tribune.

The top spot is shared by New Zealand and Denmark with 87 points each. Notably, eight out of 10 countries in the top 10 are from western or northern Europe. The bottom of the list is occupied by countries with long-lasting unstable political situation, military conflicts and uneven control of the government over the territory, such as Somalia (with a score of 9), South Sudan (12) and Syria (13).

According to the Global Corruption Perception Index, two-thirds of countries’ score are below 50 and the average score is 43.

Since 2012, only 22 countries have improved their scores. Estonia, Greece and Guyana are included in this. However, the scores of 21 countries have declined, including Australia, Canada and Nicaragua.

Since its inception in 1995, the Corruption Perceptions Index, Transparency International’s flagship research product, has become the leading global indicator of public sector corruption.

Founded in 1993, Transparency International is an international non-governmental organization based in Berlin, Germany. Its nonprofit purpose is to take action to combat global corruption with civil societal anti-corruption measures and to prevent criminal activities arising from corruption.

Because corruption is willfully hidden, it is impossible to measure directly; instead, proxies for corruption are used. Corruption is a very difficult phenomenon to measure. There have been many attempts to solve this problem but they've all come up with limitations.

CPI has been criticized on the basis of its methodology.

According to political scientist Dan Hough:

Corruption is too complex to be captured by a single score. The nature of corruption in rural Kansas will, for instance, be different from that in the city administration of New York, yet the index measures them in the same way.

By measuring perceptions of corruption, as opposed to corruption itself, the index may simply be reinforcing stereotypes and cliches.

The index only measures public-sector corruption, leaving out private actors. This, for instance, means the Libor scandal or the VW emissions scandal are not counted.